SPF 101: What You Need to Know About Sunscreen

Summer is here, and it’s more important than ever to make sure you’re practicing good sun protection habits. These longer, hotter days mean more UV exposure, which can cause serious sun damage to your skin. That sun damage piles up over time, leading to premature aging, discoloration, and an increased risk for skin cancer.

Florida Academic Dermatology Center in Coral Gables wants you to be safe while enjoying your summer. Here’s everything you need to know to find the right SPF sunscreen for you!

What Does SPF Stand For?

SPF stands for Sun Protection Factor. This measures how well a sunscreen or sunblock protects your skin from UV radiation. The number corresponding to your sun protectant’s SPF rating indicates how long it can help absorb or reflect those UV rays. 

SPF ratings work on a base of 10 – meaning the average length of time unprotected skin takes to burn from sun exposure is 10 minutes. So, a product with an SPF of 30 helps prevent sunburns for up to 300 minutes.

However, it’s important to make sure you’re using sunscreens and sunblocks properly. Applying your sun protectant isn’t a one-and-done thing; on average, you should reapply SPF every 2 hours.

Which is Better: Sunscreen or Sunblock?

Deciding between sunscreen and sunblock is a personal choice. Different products will work well for different people. That said, understanding what sets these two sun-protectant products apart can help guide your personal choice.

As the names suggest, sunscreen works by helping to ‘screen’ the amount of UV rays your body absorbs. By helping to absorb harmful sun rays, sunscreen helps to minimize possible damage. Sunblock, on the other hand, protects by reflecting UV rays before they reach the skin. While neither formulation can prevent 100% of UV rays from causing skin damage, sunblock may be more effective for people with more sensitive skin. 

Why Do I Need to Re-Apply Sunscreen?

Getting the maximum benefits of using SPF products requires you to stay on top of applying and re-applying it as needed. Why? Because, even though a product may be rated for 300 minutes of protection or longer, the more time you allow between applications, the less effective it will gradually become. 

Sweating, swimming, or other water activities can affect how well your sun protectant works. Water and the minerals in your sweat can cause them to break down more quickly, which is why it’s important to use a waterproof product and reapply more frequently if you’re engaging in these kinds of activities – about every hour.

Do I Need to Wear SPF Indoors?

That depends – if there’s a lot of natural light through windows or sliding glass doors, you may want to wear a sun protectant even indoors. Even though windows can protect against most UV rays, preveting sunburns, it’s still possible to experience sun damage indoors. 

The same is true for overcast, cloudy days. Even if you can’t physically see the sun, those powerful UV rays are still reaching your skin and can cause invisible damage over time. Introducing daily sun protection into your skincare routine is best to stay safe and protected no matter what the weather looks like.